Front derailleur issues

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iginger 11 Jan 14:12  

Joined: 21 Jan 2010

Posts: 13

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My Profile 		Hi, not sure if anyone can help, but i fitted a new crank to my 3900 Trek MTB and now the front derailleur won't push up to the biggest cog, i have checked and the new crank is the same tooth size as my old one. is it just a case of buying a new front derailleur that reaches further?

anyone have anything similar?

thanks

My Latest Route: Apr 2012 Bristol to Reading Off Road
madferret 11 Jan 14:19  

Joined: 11 Jan 2012

Posts: 7

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dont buy new one. yours just needs adjusting, lots online tutorials, ect. not hard, good luck, rember little bit at a time. gk


Pesmo 11 Jan 18:17  

Joined: 17 Jul 2010

Posts: 74

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My Profile 		Sounds like either your cable has slipped or stretched or the deailleur may have twisted slightly. Go onto Youtube as madferret says, there is plenty of advice on there. You will need to be patient when adjusting it as some are a bit of a pain to get dead right, cable tension being probably the most important factor.


iginger 12 Jan 06:03  

Joined: 21 Jan 2010

Posts: 13

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My Profile 		that's the thing, it's a new cable, and also it is set to it's furthest reach, the limit screws are as far as they go, i have even taken one out and makes no difference, it simply won't reach that far. so all i can think is that there must be one you can buy with a bigger reach, or there are issues with my crank, but that is on as far as possible, even encouraged it with a wooden mallet.

but thanks anyway

My Latest Route: Apr 2012 Bristol to Reading Off Road

skiad1 13 Jan 22:23  

Joined: 09 Dec 2011

Posts: 70

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My Profile 		you sound like you know what you're doing(minus the mallet :p) so my advice.....Next stop your lbs. They might not even charge you if it does turn out to be an adjustment issue, or similar. I'd chance it to save (potentially) on having to buy a new mech!


madferret 17 Jan 17:20  

Joined: 11 Jan 2012

Posts: 7

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did you fix it. or buy a new mech?? hope all right now?


iginger 02 Feb 11:23  

Joined: 21 Jan 2010

Posts: 13

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My Profile 		to be honest i have left it as it is, i can get the first two front cogs, and don't really use the big one anyway unless going down hill at speed. plus i've spent to much recently on bike parts, just replaced all the parts on my bike and i don't think my other half will appreciate buying a new front derailleur. :0)

cheers

My Latest Route: Apr 2012 Bristol to Reading Off Road

sdwalker 15 Feb 19:46  

Joined: 17 Mar 2011

Posts: 91

Bike:

My Profile 		highjacking your post for a similar prob I can get into top gear but shifting back down it is not moving. I did have an issue recently when the chain was shifting down, it cinked back on itself and got lodged next to the crank arm, and I am wondering if that might have done something more serious than I can fix. Any advice on what bits I should look to adjusting let me know.

My Latest Route: Mar 2012 Bedgebury Forest Red Route

qwiksilver 18 Feb 04:33  

Joined: 23 Apr 2011

Posts: 27

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My Profile 		iginger if i was you i would measure the spacing between the rings of the old crank and the new 1 if they are the same its only 1 of 2 things a fitting issue i.e you havent fitted it correct or its an adjustment issue in either case look up sheldon browns website you should find everything on there you could need to know about fixing it, as for your issue sdwalker if a chain backs/doubles up on itself theres either not enough lubricant on it, its full of muck and dirt causing it not to release from the chainring or a more serious issue but you also may find sheldon browns web site helpful good luck guys.


albion 18 Feb 17:26  

Joined: 11 Jul 2010

Posts: 87

Bike:

My Profile 		Each chainwheel has a recommended bottom bracket cartridge length.

I had a 122 mm bottom bracket and when moving to a better suited crank set I needed to buy a 113mm one. There is some tolerance in sizing but obviously not enough to cover my 9mm variation. Search the web and you will find the size best suited to your new crank set.

http://www.sheldonbrown.com/bbsize.html

My Latest Route: Feb 2012 Bowes Railway Path Start to End

leelee 16 May 23:14  

Joined: 10 Feb 2012

Posts: 14

Bike:

My Profile 		smaller hole on back of crank tighter fit will not go on as far as old crank gears set up for old crank not this one any way put bike on washing line hang under seat so back wheel up of floor loose both screws on top or side deralier put chain on top cog pull deralier with hand towards top cog till clear titen screw till not move sorr make gears slack before try pull deralier let go put chain on small front cog pull derailer same and titen other screw one screw stop it come off top cog one stop it come off small
happy cyclin if this not work then crank wedge to big or crank hole to small